From b750101eb236130cf056c675997decbac904cc49 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 17:35:18 +0200 Subject: Adding upstream version 252.22. Signed-off-by: Daniel Baumann --- man/sd_bus_new.xml | 199 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 199 insertions(+) create mode 100644 man/sd_bus_new.xml (limited to 'man/sd_bus_new.xml') diff --git a/man/sd_bus_new.xml b/man/sd_bus_new.xml new file mode 100644 index 0000000..b451061 --- /dev/null +++ b/man/sd_bus_new.xml @@ -0,0 +1,199 @@ + + + + + + + + sd_bus_new + systemd + + + + sd_bus_new + 3 + + + + sd_bus_new + sd_bus_ref + sd_bus_unref + sd_bus_unrefp + sd_bus_close_unref + sd_bus_close_unrefp + sd_bus_flush_close_unref + sd_bus_flush_close_unrefp + + Create a new bus object and create or destroy references to it + + + + + #include <systemd/sd-bus.h> + + + int sd_bus_new + sd_bus **bus + + + + sd_bus *sd_bus_ref + sd_bus *bus + + + + sd_bus *sd_bus_unref + sd_bus *bus + + + + sd_bus *sd_bus_close_unref + sd_bus *bus + + + + sd_bus *sd_bus_flush_close_unref + sd_bus *bus + + + + void sd_bus_unrefp + sd_bus **busp + + + + void sd_bus_close_unrefp + sd_bus **busp + + + + void sd_bus_flush_close_unrefp + sd_bus **busp + + + + + + Description + + sd_bus_new() creates a new bus + object. This object is reference-counted, and will be destroyed + when all references are gone. Initially, the caller of this + function owns the sole reference and the bus object will not be + connected to any bus. To connect it to a bus, make sure + to set an address with + sd_bus_set_address3 + or a related call, and then start the connection with + sd_bus_start3. + + In most cases, it is better to use + sd_bus_default_user3, + sd_bus_default_system3 + or related calls instead of the more low-level sd_bus_new() and + sd_bus_start(). The higher-level functions not only allocate a bus object but also + start the connection to a well-known bus in a single function call. + + sd_bus_ref() increases the reference + counter of bus by one. + + sd_bus_unref() decreases the reference + counter of bus by one. Once the reference + count has dropped to zero, bus is destroyed + and cannot be used anymore, so further calls to + sd_bus_ref() or + sd_bus_unref() are illegal. + + sd_bus_unrefp() is similar to + sd_bus_unref() but takes a pointer to a + pointer to an sd_bus object. This call is useful in + conjunction with GCC's and LLVM's Clean-up + Variable Attribute. Note that this function is defined as an + inline function. Use a declaration like the following, in order to + allocate a bus object that is freed automatically as the code + block is left: + + { + __attribute__((cleanup(sd_bus_unrefp))) sd_bus *bus = NULL; + int r; + … + r = sd_bus_default(&bus); + if (r < 0) { + errno = -r; + fprintf(stderr, "Failed to allocate bus: %m\n"); + } + … +} + + sd_bus_ref() and sd_bus_unref() execute no operation if + the argument is NULL. sd_bus_unrefp() will first dereference + its argument, which must not be NULL, and will execute no operation if + that is NULL. + + sd_bus_close_unref() is similar to sd_bus_unref(), but + first executes + sd_bus_close3, + ensuring that the connection is terminated before the reference to the connection is dropped and possibly + the object freed. + + sd_bus_flush_close_unref() is similar to sd_bus_unref(), + but first executes + sd_bus_flush3 as well + as sd_bus_close3, + ensuring that any pending messages are synchronously flushed out before the reference to the connection + is dropped and possibly the object freed. This call is particularly useful immediately before exiting + from a program as it ensures that any pending outgoing messages are written out, and unprocessed but + queued incoming messages released before the connection is terminated and released. + + sd_bus_close_unrefp() is similar to + sd_bus_close_unref(), but may be used in GCC's and LLVM's Clean-up Variable + Attribute, see above. Similarly, sd_bus_flush_close_unrefp() is similar to + sd_bus_flush_close_unref(). + + + + Return Value + + On success, sd_bus_new() returns 0 or a + positive integer. On failure, it returns a negative errno-style + error code. + + sd_bus_ref() always returns the argument. + + + sd_bus_unref() and sd_bus_flush_close_unref() always return + NULL. + + + Errors + + Returned errors may indicate the following problems: + + + + -ENOMEM + + Memory allocation failed. + + + + + + + + + See Also + + + systemd1, + sd-bus3, + sd_bus_default_user3, + sd_bus_default_system3, + sd_bus_open_user3, + sd_bus_open_system3, + sd_bus_close3 + + + + -- cgit v1.2.3